This research will attempt to clarify the evolutionary relationships of species within the genus Anopheles, the mosquito vectors of malaria. One major effort will be directed at mapping the salivary gland chromosomes of Anopheles, especially within the subgenus Nyssorhynchus. These neotropical anophelines, including many important vectors, constitute a "difficult" taxonomic group in that morphological characteristics exhibit a wide range of variation, with overlap, which is almost certainly genetic. Many widely-distributed species (e.g. nuneztovari, darlingi, albimanus) are almost certainly groups of sibling species which have been shown to differ in vector capacity of plasmodia. A second line of research will continue the work on enzyme polymorphism in native populations of Anopheles. Using starch gel electrophoresis, it has been possible to identify and map esterases and other enzymes, identify homozygotes and heterozygotes and estimate polymorphism in natural populations. Major efforts will concentrate in species and in species groups with known polymorphism and extensive distribution.